Consider the emergence of a pandemic, from the first spillover event to worldwide transmission. Where are the points at which we could stop the spread of the disease? Explain.

A patient in the hospital has an intravenous catheter inserted to allow for the delivery of medications, fluids, and electrolytes. Four days after the catheter is inserted, the patient develops a fever and an infection in the skin around the catheter. Blood cultures reveal that the patient has a blood-borne infection. Tests in the clinical laboratory identify the blood-borne pathogen as Staphylococcus epidermidis, and antibiotic susceptibility tests are performed to provide doctors with essential information for selecting the best drug for treatment of the infection. Antibacterial chemotherapy is initiated and delivered through the intravenous catheter that was originally inserted into the patient. Within 7 days, the skin infection is gone, blood cultures are negative for S. epidermidis, and the antibacterial chemotherapy is discontinued. However, 2 days after discontinuing the antibacterial chemotherapy, the patient develops another fever and skin infection and the blood cultures are positive for the same strain of S. epidermidis that had been isolated the previous week. This time, doctors remove the intravenous catheter and administer oral antibiotics, which successfully treat both the skin and blood-borne infection caused by S. epidermidis. Furthermore, the infection does not return after discontinuing the oral antibacterial chemotherapy. What are some possible reasons why intravenous chemotherapy failed to completely cure the patient despite laboratory tests showing the bacterial strain was susceptible to the prescribed antibiotic? Why might the second round of antibiotic therapy have been more successful? Justify your answers.

1. Draw the generalized alternation of generations life cycle all plants follow. When are plants gametophytes? Sporophytes? Know this for bryophytes (mosses), seedless vascular plants (ferns), gymnosperms and angiosperms for the exam.

What kind of chromosomal rearrangements move DNA from one chromosome to a nonhomologous chromosome?

By way of the wobble, one molecule of _____ can complement more than one _______.

7.a Robert thought Barney’s problem resided in his Nieuwkoop center. What do you think?

b Sarah thought it was a problem with his organizer. Do you agree or disagree?

c.Karen believed it was a problem with neurulation. Is this the reason?

d. What do you think is causing Barney’s problem? Do you think he can be “cured”?

These questions are form the case study: Don’t Lose Your Head A Case Study in Dorsal-Ventral Axis Formation in Amphibians

CASE STUDY BELOW

John and Heather Pipiens were very nervous. Heather had recently given birth to a good

size clutch of eggs. Most of the little larvae were doing fine. The one exception was Barney.

His head development was not like the rest of his siblings. His head seemed smaller than it

should be and he hadn’t formed his cement glands yet.

“What do you think could be wrong?” asked a very worried Heather.

“Don’t get all worked up.” Replied John. “I am sure

its nothing. He may just be a little slower than the rest of

the kids. We have 133 perfectly normal, healthy little larvae

and not all of them developed at the exact same rate.

Remember Gracie? She gastrulated almost a day later than

the rest and she’s just fine. And Jason didn’t have his first

cleavage until almost an hour after the rest and he’s doing

great.”

Just then, the nurse came out and called their name.

They were escorted into an exam room. Barney’s height,

weight and somite count were taken. The nurse then told

them that Dr. Triturus would be in a few minutes.

True to her word, the doctor came into the exam

room five minutes later. He took one look at Barney and his

heart sank. He knew something was very wrong. He was

definitely missing part of his forebrain and his entire cement

gland. Based on his somite count both should be very well developed by now

Dr. Triturus turned and looked at the Pipiens and said, “Mr. and Mrs. Pipiens, at first

glance there seems to be a problem with his developmental progress. He does have some head

development abnormalities that I don’t believe are related to timing. Everything else seems to be

ok; he has the correct number of somites for his age and his trunk seems to be developing just

fine. The problem seems to be the front most part of his head. It’s failed to develop. I don’t

know the exact caused just yet. I would like to admit him for some tests.”

“Is this necessary?” asked Barney’s mom. “How serious is it? Can it be fixed?”

“I really can’t say at this time.” replied Dr. Triturus. “I need to do some tests to get a

better idea of what is causing Barney’s problem before I can make a diagnosis. I would like you

to leave him here over the weekend. You can pick him up on Monday.”

“But we want to stay with him.” said both his mom and dad.

“That really isn’t necessary. He is still in his jelly coat and not really aware of what is

going on. Besides you have 133 other children to take care of. Go home. He’ll be in good

hands with us.”

John and Heather kissed Barney good-bye. The doctor had the nurse admit him and got

him settled in his hospital tank. He then called his students together. Dr. Triturus had a pretty

good idea of the cause of Barney’s problems, but wanted to give his residents a chance at the

diagnosis before he ran tests to confirm his hypothesis.

Dr. Triturus began, “We have a 4 day-old male anuran with abnormal head development.

He is showing an absence of forebrain development and his cement glands have failed to form.

Everything else seems to be normal. What are your thoughts?”

The med students looked at each other. Robert thought it might be a problem with his

Nieuwkoop center. Sarah thought it was probably a problem with his organizer. Karen told

them both were wrong and it had to be a problem that occurred during neurulation. It was

obvious that this group of students had no real idea what was going on.

“You are on track, just not the right one. It’s a problem with dorsal-ventral axis

formation. But it’s obvious that most of you don’t know much about the development of the

central nervous system. Go home and do some research on this and be prepared to answer some

questions during rounds tomorrow afternoon. I am disappointed about how little you seem to

know about this subject. It is one of the first developmental decisions an embryo makes and one

of its most important. Go do some research and be prepared to have better answers tomorrow.”

Dr. Triturus went over to Barney’s tank to check on him one more time. Satisfied that he

would be all right until morning, Dr. Triturus went home hopeful that his students would be

better prepared the next time they met. If not, some of them might find themselves cleaning

tanks for the next two weeks.

You are part of Dr. Triturus’s research group. You really don’t want to clean hospital

tanks for the rest of your residency. To prepare for tomorrow’s rounds answer the following

questions and be ready to provide a diagnosis of the cause of Barney’s head abnormalities. Be

prepared to justify your reasoning.

Explain how degradation of tryptophan (an amino acid) can be converted into carbohydrate (sugar) as an energy source. Use the chemical reaction and identify the metabolic pathway(s) (discussed in lecture) involved. (Hint: Deamination is involved)

in producing a transgenic plant using the Ti plasmid of Agrobacterium tumefaciens:

a)The transgene is inserted in the Ti plasmid in place of the vir region

b)The transgene releases the tumour genes present in the T-DNA of the Ti plasmid

c)The antibiotic resistance gene on the Ti plasmid is replaced witht eh EPSP synthase gene

d) The recombinant Ti plasmids is electroporated into the plant cells

e)Recombinant plant cells are selected by growth on media containing glyphosate

Please explain or diagram how specific molecules can be sorted out from a large EMS chamber (e.g., the Golgi or ER) and packaged in a vesicle.


7.) Type of presentation complex found only on macrophages, dendritic cells, and B cells.

A. Antigen

B. Epitope

C. MHC I

D. MHC II

8.) Cells that mass produce and release antibodies.

A. neutrophils

B. plasma cells

C. natural killer cells

D. macrophages

9.) Destruction of immune cells that respond to self.

A. opsonization

B. memory

C. tolerance

D. clonal selection

10.) Which class of vaccine consists of a whole pathogen that is killed or inactivated with heat, chemicals, or radiation?

A. attenuated

B. inactivated

C. subunit

D. toxoid

Dihybirds involve the inheritance of two traits, two pairs of alleles.

In humans, brown eye color (B) is dominant to blue eyes color (b) and dark hair color (D) is dominant to blond hair color (d).

1. What is the genotype of a person heterozygous for both traits?

2. What are the possible genotypes of a blue-eye, dark haired individual?

3. What are the possible genotypes of a blue-eye, dark haired individual?

4. What is the genotype of a blue-eyed blond?

5. For an individual who is heterozygous for both traits, what would be the genotypes for the FOUR possible gametes they can produce?

Construct a Punnett square for two parents who are heterozygous for both traits: BbDd x BbDd to do this, place the possible gametes of each parent on the left side and top side, above column and row, and fill in the boxes with the offspring genotypes.

How does the general model of strand invasion, branch migration, and resolution of the Holliday junction work?

Sample Random Mating Lab Drosophilla

P generation was 2 males and 2 females of dumpy, vesitgal, Black Body, Sepia eyed, Irregular facets, and white eyed.

1) In the F1 generation, the most common phenotype is usually wild type for all traits. Based on allele frequencies, why, even though no true breeding wild type flies were present in the P generation does the F1 generation usually have a majority of wild type?

11) what are the 4 stages of Demographic transition? why are they very important? discuss birth, death, and other factors that affect population size